The use of a phased array transducer comprising a plurality of adjacent transducer elements for beam focusing is well known in the ultrasonic imaging art as shown, for example, in U.S. Pat. No. 3,936,791. The sequential operation of individual transducer elements or groups of elements for beam scanning also is well known as shown, for example, in U.S. Pat. No. 4,164,213. Also, focusing means which include a separate tapped delay line for each element of a transducer array are shown in U.S. Pat. No. 4,116,229. The taps are changed for dynamically focusing from minimum to maximum range the beam. Switching of the taps occurs during the signal reception period for generation of switching transients which are potentially deleterious. Also, a large number of relatively expensive tapped delay lines are required for the beam focusing and scanning operations provided by such prior art arrangement.